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NMDA receptor activation modulates evoked release of substance P from rat spinal cord
Author(s) -
Malcangio Marzia,
Fernandes Karin,
Tomlinson David R.
Publication year - 1998
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1038/sj.bjp.0702260
Subject(s) - nmda receptor , spinal cord , neuroscience , substance p , chemistry , receptor , medicine , biology , neuropeptide
The possible modulation exerted by glutamate on substance P (SP) release from the rat spinal cord has been investigated. The N‐methyl‐ D ‐aspartate (NMDA) receptor agonist, NMDA (1 μ M ), increased SP basal outflow by 46.5 ± 10.9% ( n =3, P <0.01) without changing the evoked release of the peptide. Conversely, NMDA antagonists but not 6‐cyano‐7‐nitroquinoxaline‐2,3‐dione (CNQX) inhibited both electrically‐evoked and capsaicin‐induced release of SP. In particular, D‐2‐amino‐5‐phosphonopentanoate (D‐AP5; 50 μ M ) inhibited electrically‐evoked and capsaicin‐induced release of SP by 93 ± 2.4% and 93.2 ± 3.8% ( n =12, P <0.01), respectively. Functional pharmacological evidence is provided for glutamate exerting a positive feedback on SP release evoked by C fibre stimulation via NMDA receptor activation.